CN101509403B - Method for controlling temperature of fuel in engine pressure conduit - Google Patents

Abstract

The invention relates to a method for controlling the temperature of fuel in a pressure conduit (20) of a large crosshead type dual stroke diesel engine (1); wherein the pressure conduit (20) connects a shared fuel track (40) to a hydraulic valve actuator (19); and the method comprises the following steps: the temperature of the fuel entered into the pressure conduit (20) is controlled during the changing of the fuel running temperature so as to maintain the fuel temperature gradient below the preset threshold value.

Description

The method of the temperature of fuel in the control engine pressure piping

The application be submitted on February 2nd, 2005, application number is PCT/EP2005/001040, national applications number is: 200580047586.6, denomination of invention dividing an application for the patent application of " large-scale two-stroke diesel engine with hydraulic actuating exhaust valve ".

Technical field

The present invention relates to the large-scale two-stroke diesel engine of crosshead, specifically, relate to the method for the temperature of fuel in the control engine pressure piping.

Background technique

Prime mover that the large-scale two-stroke diesel engine of crosshead is generally used for marine propulsion and is used as the power station.These internal-combustion engines are not only constructed differently from any other internal-combustion engine because of its overall dimensions.Two stroke principle and use in the time of 50 ℃ viscosity to be lower than the heavy fuel oil (this fuel oil in room temperature time do not flow) of 700cSt are so that they constitute a class by itself in engine art.

In many such conventional engines, exhaust valve and fuel injection system are driven by the rotating cam that directly is coupled to engine crankshaft.Two-cycle engine comes the air inlet of control cylinder with scavenge port, thereby the air inlet timing is relevant with degree in crank angle rigidly.This is just so that the control that exhaust valve and fuel spray is more flexible.

For the fuel consumption of this motor, reliability and power output require high.Recently, environmental requirement has caused requirement to reduce toxic emission.In order to satisfy these sometimes conflicting requirements, with respect to traditional rotating cam drive-type exhaust valve and fuel injector, need to carry out comprehensively and flexibly controlling to fuel injection timing and emitted dose, and need to carry out comprehensively and flexibly control the aperture that opens and closes timing and exhaust valve.

Because the size of this motor, electric actuator can not be used for handling exhaust valve.In this motor of maximum, this exhaust valve 450Kg that can weigh.

MAN B﹠amp; The ME power team of W Diesel company is the crosshead type large two-stroke diesel engine with electrichydraulic control formula exhaust valve and electric liquid actuating type fuel injection system.Since the hydraulic system from the oil work of motor lubrication system.Lubricating oil system is by the low pressure pump operation of 3-4 bar.The pump of another high pressure type is transported to common rail with the pressure of about 200 bar with lubricant oil.The lubricant oil that comes from common rail is directed into the fuel pressurization device by hydrovalve, and 200 bar pressures that the fuel pressurization device is heavy with common rail are increased to needed 1000 bar pressures in the burning line.Burning line is heated to 90-150 ℃ to guarantee that fuel oil can flow and have suitable viscosity.The lubricant oil that comes from common rail is directed into hydraulic exhaust valve actuator with operations platoon's valve by the timing valve.

Yet the lubricant oil that comes from the lubrication system of these motors is not clean must being enough to be used in the common rail hydraulic system.Thereby need filtering lubricant oil, to remove any particle on the 5-10 μ before common rail can being pumped at it.

The RT-flex Engine Series is the crosshead type large two-stroke diesel engine with electrichydraulic control formula exhaust valve and electric liquid startup formula fuel injection system.The hydraulic system that is used for valve actuation operates with specific hydraulic fluid.Lubrication system is separated with hydraulic system fully.

EP 1 130 251 discloses a kind of pump-unit of the accumulator for being provided at the common rail system that the large-scale two-stroke diesel machine uses, and this pump-unit has: at least two pumps are used for transporting fluid into accumulator; With middle accumulator, be used for buffering power press member, wherein each pump is connected to described middle accumulator via independent pump line line.Can use three pumps and pipeline, described pipeline has the safety check that is connected to described intermediate receptacle at the place, end.Simple close/open valve to the mobile valve of controlling of fuel from common rail to each cylinder.

DE 103 11 493 discloses a kind of large-scale two-stroke diesel machine, and it has at least one cylinder, and described cylinder is provided with exhaust port, and the piston of controlling this exhaust port slidably is contained in wherein.Outlet valve activates by hydraulic actuator and cuts out exhaust outlet and by Proportional valve that hydraulic actuator and fuel-injection pump shared.This Proportional valve has the entrance and two outlets that are connected to hydraulic actuator and fuel-injection pump that are connected to high-pressure fluid source.

EP 1 471 236 discloses a kind of fuel system for motor car engine and fuel feeding method.In order to carry out the fuel injection from starting in the range of operation of keeping operation by abundant expansion under the fuel pressure high as needed, the fuel fuel supplying system that is used for direct fuel injection type internal-combustion engine is provided with high pressure fuel pump and will be ejected into the firing chamber of motor from sparger by the fuel of high pressure fuel pump pressurization with direct.Electric motor is arranged to the auxiliary drive high pressure fuel pump.When engine start, by auxiliary power unit Execution driven high pressure fuel pump or the help driving high pressure fuel pump of for example electric motor.

GB 2 102 065 discloses a kind of pneumatic biasing arrangement, and it comprises because valve is opened and compressed gas volume.Compressed gas volume acts on the cap that is fixed to valve rod, with valve rod vertically apply a power, thereby valve is biased to its closed position, wherein valve head is extruded and is close to valve seat.

WO0012895 discloses a kind of system be used to making the traveling priority valve deceleration of carrying out closing movement.This system comprises housing, be arranged on the first hydraulic fluid chamber in the described housing and be used for moving according to the hydraulic fluid that is fed to described the first hydraulic fluid chamber the relay piston of this valve.The deceleration of valve can realize from the hydraulic fluid that the first Room is discharged into the second Room by throttling optionally.The closing movement of the hydraulic fluid opposing valve in the second Room, thus make it slack-off to realize taking one's seat of valve gradually.Throttling gradually is used for during taking one's seat at the second indoor maintenance constant hydraulic pressure almost.Throttling gradually can be by selecting suitable throttle orifice size and dimension and the suitable throttling that is used for the hole distribute and realize.

US 2002/0184996 discloses a kind of actuator, and it comprises cylinder, first, second, and third opening, power piston, control piston and control spring.This cylinder defines longitudinal axis and comprises the first and second ends.The first opening is communicated with the first end of described cylinder, and the second opening is communicated with the second end of described cylinder, and the 3rd opening is communicated with between the first and second ends with described cylinder.Power piston is arranged in the cylinder and can moves in the first and second directions along longitudinal axis.Power piston comprises the first and second sides.Control piston also is arranged in the cylinder and can moves in the first and second directions along longitudinal axis.Control piston comprises the first and second sides, and the first side of this control piston is towards the second side of power piston.Control spring is in one of them this control position of direction upper offset of the first and second directions.The method of controlling this actuator also is provided.

Summary of the invention

Based on above-mentioned background, the purpose of this invention is to provide a kind of to the fuel temperature in the supply line of crosshead type large two-stroke diesel engine control method.

This purpose realizes by the method that the temperature of fuel in a kind of pressure piping of controlling crosshead type large two-stroke diesel engine is provided, described pressure piping is connected to hydraulic exhaust valve actuator with common fuel rail, and the method running temperature of being included in fuel change during the control temperature that enters into the fuel of pressure piping maintain step under the predetermined threshold with the temperature gradient with described fuel.

Thereby fuel can be used as hydraulic medium, is used for operation for the exhaust valve actuator of the sensitive of running temperature.

Another object of the present invention provides a kind of crosshead type large two-stroke diesel engine, and it has can be with the hydraulic pressure exhaust valve actuating system of many kinds of liquid hydraulic fluid operation.

This purpose is by providing a kind of crosshead type large two-stroke diesel engine to realize, described crosshead type large two-stroke diesel engine comprises: the crankcase support, and it supports bent axle and the air cylinder support that is installed on the described crankcase support; A plurality of cylinders, it is supported by described air cylinder support, and each cylinder is provided with at least one fuel injector and at least one exhaust valve; The hydrovalve actuator that is associated with each described exhaust valve; Common fuel rail, it has one or more accumulators that are connected thereto; High pressure fuel pump, it under high pressure supplies fuel to described common fuel rail, each described sparger is to come from the operating fuel of described common rail, described hydrovalve actuator is connected to described common rail by corresponding hydraulic line, and finally be connected to for example other hydraulic unit of valve, it is characterized in that static gasket that pipeline and the connection between other hydraulic unit to described motor seal and the dynamic packing ring in the described valve actuator made by following material: cast iron, steel, teflon (PTFE), fluorine rubber, (FPM), copolymer (NBR), nitrite rubber, poly-(dimethyl siloxane) (SI) or its composition and/or mixture.

From these materials selected packing ring allow non-dedicated hydraulic fluid for example fuel can be used in the hydraulic system, described fuel can not cause damage to packing ring.

Another object of the present invention provides a kind of crosshead type large two-stroke diesel engine, and described crosshead type large two-stroke diesel engine has can be with the hydraulic pressure exhaust valve actuating system of many kinds of liquid hydraulic fluid operation.

This purpose is by providing a kind of crosshead type large two-stroke diesel engine to realize, described crosshead type large two-stroke diesel engine comprises: the crankcase support, and it supports bent axle and the air cylinder support that is installed on the described crankcase support; A plurality of cylinders, it is supported by described air cylinder support, and each cylinder is provided with at least one fuel injector and at least one exhaust valve; The hydrovalve actuator that is associated with each described exhaust valve; Common fuel rail, it has one or more accumulators that are connected thereto; High pressure fuel pump, it under high pressure supplies fuel to described common fuel rail; Be used for fuel is transported to supply line and control valve unit respective injectors, that be associated with each cylinder from described common rail; Be used for fuel is transported to supply line and control valve unit the respective hydraulic valves actuator, that be associated with each cylinder from described common rail; With the heating reflux line, be used for fuel is sent to fuel tank or is sent to the pipeline of the entrance that leads to described high-pressure service pump from described hydrovalve actuator.

Thereby, have low viscous HFO and can be used as hydraulic medium.

Another object of the present invention provides a kind of crosshead type large two-stroke diesel engine, and described crosshead type large two-stroke diesel engine has the hydraulic pressure exhaust valve actuating system that can move in large temperature range.

This purpose is by providing a kind of crosshead type large two-stroke diesel engine to realize, described crosshead type large two-stroke diesel engine comprises: the crankcase support, and it supports bent axle and the air cylinder support that is installed on the described crankcase support; A plurality of cylinders, it is supported by described air cylinder support, and each cylinder is provided with at least one fuel injector and at least one exhaust valve; The hydrovalve actuator that is associated with each described exhaust valve; Common fuel rail, it has one or more accumulators that are connected thereto; High pressure fuel pump, it under high pressure supplies fuel to described common fuel rail; Be associated with each cylinder, be used for fuel is transported to corresponding injector pressure pipeline and control valve unit from described common rail; The supply line and the control valve unit that are used for fuel is transported to from described common rail the respective hydraulic valves actuator that are associated with each cylinder; And reflux line, be used for fuel is sent to fuel tank or is sent to the pipeline of the entrance that leads to described high-pressure service pump from described hydrovalve actuator, wherein at least one described pipeline comprises for eliminating because the device of the impact of the line size variation that the variation of running temperature produces.

Thereby described hydraulic system can be moved and guarantee can not produce mechanical stress owing to the dimensional changes that temperature causes in large temperature range.

Another object of the present invention provides a kind of new purposes of Proportional valve.

This purpose realizes that by a kind of purposes that Proportional valve is provided it is used for controlling fuel from common fuel pipeline the flowing to fuel injector and/or operating fuel parts of crosshead type large two-stroke diesel engine.

Another object of the present invention provides a kind of electrical control valve, is used for control fuel from common fuel pipeline the flowing to one or more operating fuels or fuel consumption engine components of crosshead type large two-stroke diesel engine.

This purpose is by providing a kind of electrical control valve to realize, described electrical control valve is used for control fuel from common fuel pipeline the flowing to one or more operating fuels or fuel consumption engine components of crosshead type large two-stroke diesel engine, this electrical control valve comprises valve body and electromagnet (solenoid), and described electromagnet and described valve body are adiabatic thus.

Another object of the present invention provides a kind of crosshead type large two-stroke diesel engine, and described crosshead type large two-stroke diesel engine has improved hydraulic system circulation when engine stop.

This purpose is by providing a kind of crosshead type large two-stroke diesel engine to realize, described crosshead type large two-stroke diesel engine comprises: the crankcase support, and it supports bent axle and the air cylinder support that is installed on the described crankcase support; A plurality of cylinders, it is supported by described air cylinder support, and each cylinder is provided with at least one fuel injector and at least one exhaust valve; Common fuel rail; And high pressure fuel pump, it under high pressure supplies fuel to described common fuel rail at the motor run duration; The supply line and the control valve unit that are associated with each cylinder, be used for fuel is transported to from described common rail respective injectors; Described high pressure fuel pump is mechanically driven and is electrically driven by electric motor during engine stop by described bent axle at the motor run duration, with under low pressure so that fuel passes described supply line and/or described common rail and/or passes with other engine components of operating fuel circulates.

By using high-pressure service pump to provide circulation as high-voltage power supply and low pressure source during engine stop, part count is reduced, thereby so that unitary construction and maintenance cost have more competitiveness.

Another object of the present invention provides a kind of hydraulic actuating scavenging air valve, and it is for the internal-combustion engine of the pneumatic spring with improvement.

This purpose is by providing a kind of hydraulic actuating scavenging air valve for internal-combustion engine to realize that described hydraulic actuating scavenging air valve comprises: static valve body; Scavenging air valve, it can move between the position take one's seat position and non-taking one's seat, and comprises microscler valve rod, and this microscler valve rod one end has valve head, has free terminal in the opposite end; Hydraulic actuator, described hydraulic actuator comprises the piston on the free terminal that acts on described valve rod, is used for when described hydraulic actuator is supplied with pressurized hydraulic fluid described valve urged the non-position of taking one's seat; Pneumatic spring, it urges the described position of taking one's seat with described valve, and described pneumatic spring comprises: cylinder, it is fixed to described valve rod, and described cylinder is sealing towards the direction of the free terminal of described valve rod, is opening wide towards the direction of described valve head; And the stationary piston of coupling, it is contained in the described cylinder, and described piston is fixed to described valve body and is formed for the spring housing of described pneumatic spring with described cylinder.

The structure of described pneumatic spring has reduced the chance that the hydraulic medium that comes from described actuator enters described spring housing.

Another object of the present invention provides a kind of improvement hydraulic actuating scavenging air valve for internal-combustion engine.

This purpose is by providing a kind of hydraulic actuating scavenging air valve for internal-combustion engine to realize that described hydraulic actuating scavenging air valve comprises: static valve body; Scavenging air valve, it can non-ly take one's seat mobilely between the position what take one's seat position and described valve that described valve cuts out were opened, and comprises microscler valve rod, and this microscler valve rod one end has valve head, has free terminal in the opposite end; Hydraulic actuator, described hydraulic actuator comprises the piston on the free terminal that acts on described valve rod, is used for when described hydraulic actuator is supplied with pressurized hydraulic fluid described valve urged the non-position of taking one's seat; Pneumatic spring, it urges the described position of taking one's seat with described valve, and wherein said valve is determined by the reverse equilibrium of forces of described hydraulic actuator and described pneumatic spring in the described running length of opening on the direction.

Thereby described actuator need to not arrange the end of travel snubber at the described end of opening stroke, and need to be in the described terminal suddenly supply of cutoff high hydraulic fluid of opening stroke.The end of travel snubber is not set has reduced mechanical load and vibration, not rapid cutoff high hydraulic fluid has been avoided the potential destructive hydraulic shock ripple that has simultaneously.

Another object of the present invention provides a kind of hydraulic actuator of the scavenging air valve for internal-combustion engine, and it can accurately operation in large temperature range.

This purpose realizes by the hydraulic actuator that a kind of scavenging air valve for internal-combustion engine is provided, described hydraulic actuator comprises: static cylinder, the far-end that it has near-end and opens wide, and comprise and can alternately be connected to source of high pressure hydraulic fluid or be connected to the pressure chamber of reflux pipeline via control valve unit; Piston, it has the near-end that is contained in the described main pressure chamber and acts on far-end on the free terminal of valve rod of described valve, when being used for being connected to described source of high pressure hydraulic fluid in described pressure chamber described valve is urged the non-position of taking one's seat, described piston comprises first portion and second portion, described first portion extends towards described near-end from described far-end, and described second portion is arranged on described proximal end, described second portion slidably engages described first portion, thereby forms the compensated chamber between described first portion and the described second portion; Spring assembly, it urges described first portion and second portion makes it away from each other, thereby described compensated chamber is enlarged; The first flow path, it is between described compensated chamber and described pressure chamber, described the first flow path is only opened when described second portion is positioned at the little axial range of being scheduled in the proximal end of described cylinder, discharges from described compensated chamber to allow excessive hydraulic fluid; The second flow path, it is between described compensated chamber and described pressure chamber, and described the second flow path allows described compensated chamber to refill under the effect of described spring assembly.

Described compensated chamber guarantees that described actuator piston always starts the position in axial range, and this causes turning back to suitable position, and wherein said valve head accurately is positioned on the described valve seat.Described compensated chamber is depended on during opening or in the Volume Changes of down periods in position in the axial range.These Volume Changes can be positive or negative during two parts of described circulation.

Another object of the present invention provides a kind of hydraulic actuator of the scavenging air valve for internal-combustion engine, described hydraulic actuator can overcome the large reaction force when beginning in the opening procedure, and in case described scavenging air valve is opened, the in check power of direction conveying will opened.

This purpose realizes by the hydraulic actuator that a kind of scavenging air valve for internal-combustion engine is provided, described hydraulic actuator comprises: static cylinder, and it comprises the pressure chamber that can alternately be connected to source of high pressure hydraulic fluid via the first opening in the described cylinder or be connected to reflux pipeline; Piston, it is contained in the described pressure chamber and acts on the end of valve rod free of described valve, when being used for being connected to described source of high pressure hydraulic fluid in described pressure chamber described valve is urged the non-position of taking one's seat, described piston can be axially mobile between the extended position that extended position that described valve is taken one's seat and described valve are opened, described piston has the first useful area, when described piston is between described retracted position and predetermined neutral position, described pressurized hydraulic fluid in the described pressure chamber acts on described the first useful area and urges described piston towards described extended position, described piston has the second useful area less than described the first useful area, when described piston was between described neutral position and described extended position, the described pressurized hydraulic fluid in the described pressure chamber acted on described the second useful area and urges described piston towards described extended position.

The acting in conjunction of described first and second effective piston areas, be described piston by the total area of described high pressure pressure fluid effect so that during the first portion that opens motion of described scavenging air valve, produce large actuation force, and the effect of described second effective piston area has been carried out good control at the remaining part of opening motion of described scavenging air valve individually.

In the following detailed description, other purpose, feature, advantage and the characteristic of described large-scale two-stroke diesel engine and operating method thereof will become more obvious.

Description of drawings

In the detailed description part below the present invention, the illustrative embodiments that illustrates with reference to the accompanying drawings illustrates in greater detail the present invention, wherein

Fig. 1 illustrates the plan view of cylinder profile in two stroke crosshead engines with cylinder head,

Fig. 2 illustrates the cross-sectional view of the cylinder profile in the motor shown in Figure 1,

Fig. 3 is the schematic representation of the hydraulic and lubricating system shown in Fig. 1,

Fig. 4 is another mode of execution of the schematic representation of the hydraulic and lubricating system shown in Fig. 3,

Fig. 5 illustrates the cross-sectional view of pressure tube used herein,

Fig. 6 is another cross-sectional view, and alternative pressure tube used herein is shown,

Fig. 7 is the longitdinal cross-section diagram of the first mode of execution of the hydraulic braking formula exhaust valve of cylinder among Fig. 2, wherein valve take one's seat and piston at its retracted position,

Fig. 8 illustrates the typical opening curves according to exhaust valve actuator of the present invention,

Fig. 9 illustrates the cross-sectional view of actuator shown in Figure 7 with larger ratio, and wherein piston is positioned at the position that part is extended,

Figure 10 illustrates the view same with Fig. 9, and wherein piston is positioned at the extreme higher position at retracted position and piston cap in its axial range,

Figure 11 is the detailed view on the top of actuator, and wherein piston roughly is in a retracted position and piston cap roughly is in the extreme higher position of its axial range,

Figure 12 is the detailed view on the top of actuator, and wherein piston is in a retracted position and piston cap roughly is in the extreme lower position of its axial range, and

Figure 13 is the detailed view on the top of actuator, and wherein piston is in a retracted position and piston cap roughly is in the neutral position of its axial range.

Embodiment

Fig. 1 illustrates according to motor 1 of the present invention.This motor is low speed two stroke cross-head diesel engines, and it can be propelling motor in the boats and ships or the prime mover in the power plant.These motors have 6 to 16 cylinder in lines usually.This motor is made at the base 2 that has for the main bearing of bent axle 3.This base is divided into the part with suitable dimension according to available manufacturing equipment.The A type crankcase support 4 of welding design formula is installed on the described base.Air cylinder support 5 is installed on the top of crankcase support 5.The stretching screw (not shown) is connected to air cylinder support with base and described structure is kept together.Cylinder 6 is by air cylinder support 5 carryings.

Fig. 2 illustrates the cylinder 6 of internal-combustion engine.Cylinder 6 is for the type of one-way flow and have the relief opening 7 that is arranged in air tank 8, and this air tank is supplied with waste gas by turbosupercharger 10 (Fig. 1) supercharging from waste gas reception unit 9 (Fig. 1).Unshowned crosshead couples together piston rod 14 and bent axle 3 (Fig. 1).

Exhaust valve 11 medially is installed on the top of cylinder in cylinder head 12.In the latter stage of expansion stroke, exhaust valve 11 is opened through before the exhaust outlet 7 downwards at engine piston 13, thus, the combustion gas in the firing chamber on the piston 13 flow out by the exhaust passage 16 of leading to waste gas reception unit 17, and the earth pressure release in the firing chamber 15.Exhaust valve 11 cuts out again in adjustable moment during piston 13 moves upward, and this moment can for example be depended on the needed effective compression ratio of burning subsequently.During this closing movement, exhaust valve is upwards driven by pneumatic spring 18.

Consider the durability of valve 11 and consider favourable, accurate control to state in the firing chamber, and then consider the efficient of motor, can advantageously very accurately control exhaust valve 11.

Exhaust valve 11 is opened by hydraulic driving actuator 19.Hydraulic fluid (fuel) is by pressure piping 20 supply, and this pressure piping is connected to the entrance on the actuator 19 in the control mouth on the upper surface of the allocation block 21 that is supported by operating console 22.Reflux line 43 is connected to the outlet on the actuator 19 refluxing opening on the upper surface of allocation block 21.

Each cylinder 6 is provided with two or three spargers 23 (only illustrating) that connected by the circulating line (not shown).Fuel is fed to sparger 23 from allocation block 21 via service 24.Sparger 23 is connected to refluxing opening on the allocation block 21 via reflux line 49.

Operating console 22 is connected to the reflux line that leads to supply line and is connected to common fuel rail (being not shown among 40, Fig. 2 among Fig. 3).

Being connected of common fuel rail 40 (Fig. 3) (not shown) in the allocation block 21 carrying proportional control valves 25, the mouth on proportional control valve 25 control allocation blocks 21 tops and reflux line (being 43 among Fig. 3) and operating console 22.

In operating console 22, from the passage 41 (Fig. 3) of common fuel rail 40 branches pressurized hydraulic fluid is sent to entrance on the proportional control valve 25.

Fuel in the common fuel rail 40 (Fig. 3) comes driven valve actuators 19 also to sparger 23 fuel supplying as hydraulic fluid.Pressure in the common rail 40 changes according to the running state of the motor 1 of for example motion speed and loading condition.Typically, the pressure in the common fuel rail 40 changes between 600 bar to 2000 bar.

Each cylinder 5 of motor 1 is associated with electronic control unit 26, and this electronic control unit receives total synchronous and control signal by cable 27, in addition, also by cable 28 electronic control signal is sent to proportional control valve 25.Can be provided with a control unit 26 for each cylinder, perhaps several cylinders are associated with same control unit (not shown).Control unit 26 also can receive signal from the overall control unit (not shown) that all cylinders share.

With reference to Fig. 3, show hydraulic system and the lubrication system of motor 1 with the form of block diagram.Hydraulic system is as fuel injection system and as exhaust valve actuating system.

Lubrication system comprises lubricating oil tank, filter and electric driving low pressure pump.Lubrication system is separated fully with hydraulic system.

Hydraulic system is with operating fuel, typically is HFO (water emulsification with not emulsification of water).The frequent emulsification of water is in HFO, to reduce the NOx discharging.This emulsification occurs in (not shown) in the independent emulsification unit.Be used for the fuel reservoir of motor operation at heating cabinet 29.The fuel that uses is commonly called heavy fuel oil (HFO), and its viscosity in the time of 50 ℃ is 500-700cSt, and at room temperature can not flow.HFO in the case is maintained at about 50 ℃ if having time in institute basically, namely also is like this during engine stop.Typically, the steamer with such motor is provided with generator set (Genset), and the miniature diesel engine of electric power and heat namely is provided to steamer and master motor at the master motor stopping period.

HFO leads to filter or centrifuge 30 from heating cabinet, and leads to preheater 31.The temperature of controlling the HFO that leaves preheater 31 according to running state and the grade of HFO.During engine stop, when HFO circulated with low pressure in hydraulic system, the temperature of HFO remained in 45-60 ℃ the scope.At the motor run duration, according to the viscosity of HFO, the temperature of leaving the HFO of preheater 31 is remained between 90-150 ℃.The measurement of sensor (not shown) is close to the viscosity of HFO of the downstream part (or other correct position) of preheater 31.The temperature of leaving the HFO of preheater 31 typically is controlled as so that in the scope of viscosity at 10-20cSt of measurement point.

Fork-shaped intermediate conduit 32 is connected to high pressure fuel pump 33 and auxiliary low pressure circulation pump 34 with preheater.Pipe downstream at each pump arranges safety check 35, to prevent back suction.

At the motor run duration, high pressure fuel pump 33 is driven via gear 37 by the gear 33 on the bent axle 3.Thereby high pressure fuel pump 33 produces the rated pressure of 1000-1500 bar, but this pressure can be according to operating conditions fluctuation between the 600-2000 bar.

During engine stop, auxiliary low pressure circulation pump 34 is driven by electric motor 38.Thus, transmit the pressure of about 3-10 bar, so that HFO is circulated in hydraulic system.

Common fuel rail 40 is extended along all cylinders, and with Fig. 3 in represent being connected by the short vertical curve that stretches out from this common rail of unshowned cylinder 6.

Cylinder 6 shown in Fig. 3 is supplied with HFO by supply line 41, and supply line 41 is from common rail 40 branches and lead to the entrance of proportional control valve 25.Supply line 41 is provided with a plurality of fluidic accumulators 42, and it carries most of fluid when proportional control valve 25 is opened, and when proportional control valve 25 cuts out from common rail 40 rear supplies (post-feed).

Pressure piping 20 is with an entrance that is connected to hydraulic actuator 19 in two outlets of proportional control valve 25.Service 24 is connected to sparger 23 with in these two outlets another.Two control mouthful is connected to corresponding exhaust port on the upper surface of allocation block by the passage in the allocation block on the proportional control valve 25.Proportional control valve 25 also has two outlets, is connected to the reflux line 43 for the hydraulic fluid of using (HFO).

Proportional control valve 25 is the Electromagnetic Drive servovalves with three positions.Electromagnet 44 via electric wire 28 from control unit 26 (Fig. 2) reception control signal.Electromagnet 44 is installed to the housing of proportional control valve 25, is provided with ceramic plate 45 therebetween, so that electromagnet 44 and proportional control valve 25 thermal insulation, proportional control valve 25 may reach at the motor run duration and surpass 150 ℃ temperature.This structure prevents that responsive electromagnet 44 is overheated.According to another mode of execution (not shown), electromagnet 44 is connected to valve body by heat insulating washer.

At middle position, wherein electromagnet 44 is inoperative, two entrance sealings of proportional control valve 25, and two outlets of proportional control valve 25 are connected to reflux line 43.When shifting left side (left side among Fig. 3) onto when the electromagnet startup and with guiding valve (valve spool), the entrance of proportional control valve is connected to pressure piping 20, and high pressure HFO is sent to this pressure piping 20, so that actuator 19 is opened exhaust valve 11.In this position, service 24 is connected to reflux line 43.When shifting right side (right side among Fig. 3) onto when electromagnet 44 startups and with guiding valve, the entrance of proportional control valve 25 is connected to service 24, and high pressure HFO is sent to this service 24, so that sparger 23 injects fuel in the firing chamber 15.In this position, pressure piping 20 is connected to reflux line 43.The shape of the volume of fuel injection timing, institute's burner oil and injection scheme (injectionpattern) is by proportional valve control.According to another preferred implementation, (unshowned) fuel flowing from the common fuel rail to the sparger controlled by close/open valve.This close/open valve can be the mobile valve of the controlling valve independently mutually that goes out hydraulic actuator with the convection current influent stream.

The mobile independently valve of controlling that the convection current influent stream goes out actuator can also be close/open valve.

Traditional fuel limiter 46 is placed in the pressure piping 24, when long-time to open mistakenly at proportional control valve, avoids excessive HFO to enter cylinder.

Pressure in the reflux pipeline 43 keeps the several bar of overvoltage, avoiding air penetration in hydraulic system, and prevents that the water among the water transfer emulsification HFO from forming steam bubble.Guarantee that at the pressure controlled valve 47 at reflux line 43 downstream end places the minimized overvoltage of being scheduled to remains in the reflux line 43.Overvoltage in the reflux line 43 is preferably the 3-10 bar.Accumulator or expansion tank 48 are connected to reflux line 43, to be absorbed in the pressure surge that may occur when proportional control valve 25 changes the position.

The second reflux line 49 is connected to reflux line 43 with the outlet of sparger 23.At the downstream part of pressure controlled valve 47, reflux line 43 will supply to preheater 31 with the HFO that crosses, to finish this circulation.

HFO is sent to common rail 40 and via the install pipeline that proportional control valve 25 is sent to hydrovalve actuator 19 and sparger 23 heating equipment that is represented by the heating coil shown in Fig. 3 is arranged from common rail 40 from the outlet of preheater 31.This pipeline can for example be heated by steam tracing or by electrical heating elements on its total length.Heat loss when the heating of these pipelines is moved from preheater downstream for the HFO that reduces heat.At the motor run duration, remain near 150 ℃ towards the temperature of the ducted HFO of sparger and hydrovalve actuator, yet this depends on the viscosity of the HFO that uses.The adjacent channel that extends in parallel in the part of its length for example pressure piping 20 and service 24 can be provided with shared heating equipment (not shown).

Reflux pipeline 43 and 49 also is provided with the as mentioned above heating equipment of same-type.The temperature of HFO is so crucial in reflux pipeline, and heating equipment is adjusted to the temperature of guaranteeing HFO and can be lower than 50 ℃.

During engine stop, HFO enters hydraulic system to avoid air, and avoids HFO Local cooling and sclerosis under the effect of recycle pump 34 and pass hydraulic system circulation (with the lower pressure of 3-10 bar).During engine stop, the Temperature Setting that leaves the oil of preheater 31 is being about 50 ℃, solidifies to avoid HFO.

At circulation period, in order not only to arrive sparger 23 but also arrive hydraulic actuator 19, proportional control valve periodic variation position.According to another mode of execution, this proportional control valve is provided with the 4th bypass position (not shown).In this position, proportional control valve leads to sparger and hydrovalve actuator simultaneously.According to another one mode of execution (not shown), independent by-pass valve is set, it allows HFO side by side to flow to sparger and hydrovalve actuator from common rail.

Heated pressure pipeline 20 is provided with device, so that this pipeline can move in about 150 ℃ temperature range of motor run duration from 50 ℃ of circulation period.After the temperature of engine stop and HFO was elevated to about 150 ℃ from about 50 ℃, thermal expansion was so that the length of pressure piping 20 increases, and vice versa.

As shown in Figure 5, pressure piping 20 is provided with one or more U-shaped parts 50, the difference of length when it can be absorbed in different running temperature by the flexibility of U-shaped part.Alternately, perhaps combine, need to can between two carriages 51 and 52, axially freely overhang in the part of the pressure piping 20 that moves under low temperature and the high temperature and other pipeline, as shown in Figure 6.Each carriage comprises lining 53, holds an end of pressure piping 20 in the lining 53, so that pressure piping 20 is fixed diametrically but is removable in the axial direction.By cast iron, steel, teflon (PTFE), fluorine rubber, (FPM), copolymer (NBR), nitrite rubber, poly-(dimethyl siloxane) (SI) or the O shape circle 54 made of similar material or similar packing ring guarantee between pipe end and the lining basically airtight sealing.The pressure that is applied on two relative free ends of pipeline 20 balances each other.The Axial changes of pipeline 20 length is absorbed by the pipe end that it axially freely overhangs.

Packing ring in the hydraulic system from cast iron, steel, teflon (PTFE), fluorine rubber, (FPM), copolymer (NBR), nitrite rubber, poly-(dimethyl siloxane) (SI), select its mixture or the similar material, with basically airtight sealing between the parts of guaranteeing hydraulic system.Concrete packing ring is described with reference to Fig. 9 below.

Fig. 4 shows another preferred implementation of hydraulic system.This mode of execution is basically identical with the mode of execution shown in Fig. 3, yet high-pressure service pump 33 also is used as the low pressure pump that makes the HFO circulation during engine stop.Here, the clutch 56 by central unit control is arranged between gear 37 and the high-pressure service pump 33.At the motor run duration, clutch 56 engages, and high-pressure service pump 33 is driven by bent axle 3.During engine stop, clutch 56 is disengaged.Another clutch 55 by central unit control is arranged between high-pressure service pump 33 and the electric motor 38 '.Clutch 55 is disengaged at the motor run duration, engages during engine stop.Electric motor 38 ' is at engine stop drive high-pressure service pump 33, and is still much lower than its motion speed at the motor run duration, is used for HFO with the pressure circulation of 3-10 bar so that enough hydraulic pressures to be provided.

The below describes the preferred implementation of actuator 19 and pneumatic spring 18 in detail with reference to Fig. 7-11.

Exhaust valve 11 has the bar 57 that extends straight up from valve head 58, and the upper end of bar 57 supports the cylinder 59 that firmly is installed on the valve rod 57, thus mineralization pressure sealing and on stationary piston 60, vertically can moving.Stationary piston 60 is parts of spring housing 61.Have the spring housing 62 that is connected to forced air feeding mechanism (not shown) in stationary piston 60, fill with for example forced air of the predetermined minimum pressure of 4.5 bar overvoltages this forced air feeding mechanism keep-spring chamber 62.Also can use other air pressure, for example the 3-10 bar.Pressure minimum is selected according to the required elastic characteristic of pneumatic spring.Can the spring housing on a plurality of different cylinders is interconnected, but preferably, each spring housing is cut off individually by the safety check 63 at forced air feeding mechanism place.Forced air in the spring housing 62 produces the power that makes progress that continues at cylinder 59.Should power upwards when moving down, cylinder 59 increase, and the air in the extrusion spring chamber 62, safety check 63 prevents that the air in the spring housing 62 from flowing out.

Spring housing 61 defines around pneumatic spring 18 and the chamber 64 that is located thereon.Chamber 64 is connected to discharge portion 65, so that this chamber has barometric pressure.Any oil that leaks from actuator 19 will enter chamber 64, and discharge via discharge portion 65.This spring is configured to leak oil and is difficult to enter spring housing 62, because cylinder 59 forms umbrella, it forces and leaks the bottom that oil flows through and arrive chamber 64 thereon downwards, and can not have the risk that enters spring housing 62.This is very important, because when leakage oil is attempted to pass even further entered pneumatic system, leaks oily (HFO) and can assemble and sclerosis or obstruction Pneumatic pipe in spring housing.

With reference to Fig. 7 and 9, hydrovalve actuator 19 is by cylinder 66 structures, and this cylinder is by the top braces of housing 61.Piston 67 is contained in the central hole of cylinder 66.This central hole seals at the place, top of cylinder 66, and opens wide at the place, bottom of cylinder 66.Hole 68 in this central hole and the housing 61 arranges coaxially.Upper (closely) end of piston 67 is contained in this central hole, and the far-end of piston 67 acts on the top of valve rod 57.

Main pressure chamber 69 limits between the top of cylinder 66 and piston 67.Hydraulic fluid (HFO) is supplied to the hydrovalve actuator via opening 70 and discharges from the hydrovalve actuator.Opening 70 is passed into intermediate pressure chamber 71, this intermediate pressure chamber be arranged under the main pressure chamber 69 and be defined in cylinder 66 and the intermediate portion of piston 67 between.Opening 70 is by proportional control valve control and alternately be connected to pressure piping 20 and reflux line 43, and this proportional control valve is exemplarily illustrated as close/open valve 25 ' in this view, although also usage ratio valve alternatively.Aux. pressure chamber 73 is defined between the respective diameters enlarged portion of the enlarged diameter part 74 of piston 67 and central hole.Alternatively, packing ring 68 ' can be arranged between enlarged diameter part 74 and the cylinder 66, with the amount of the leakage oil that reduces to enter chamber 64.During the first portion that opens stroke of hydraulic actuator 19, the axial passage 75 that aux. pressure chamber 73 forms through the recess 75 by piston 67 is supplied with the high pressure HFO from medial compartment 71.During opening stroke, closed by the control flange 76 on the cylinder 67 at predetermined neutral position axial passage 75.Simultaneously, opening 77 is connected to reflux pipeline 43 with aux. pressure chamber 73, because the top edge of enlarged diameter part 74 is positioned under the top edge of opening 77 now.Thereby enlarged diameter part 74 helps to overcome during the first portion that opens stroke of hydraulic actuator 19 by the pressure in the firing chamber 15 and is applied to larger power on the valve head 58.In the predetermined neutral position of piston 67, the supply discontinuity of arriving the high-pressure liquid of ancillary chamber 73, and this aux. pressure chamber is emptying via opening 77.The present pressure drop in the firing chamber 15, and no longer need the effect of enlarged diameter part 74.

Fig. 8 shows the typical opening curves figure of exhaust valve.In Phase I, the beginning section of opening motion need to obtain larger power from hydraulic actuator 19, overcoming the pressure in the firing chamber 15, and is used for making heavier exhaust valve 11 to accelerate.In this stage, hydraulic actuator 19 must provide maximum power.Yet, should avoid the hydraulic shock ripple that produces owing to opening fast of control valve 25 or 25 '.In Phase, exhaust valve 11 arrives the position of opening fully, and in this stage, and exhaust valve 11 is should be little by little slack-off and stop, and preferably, can not abut against each other with other object.In Phase I, the return movement of exhaust valve 11 should gently begin, the hydraulic pressure ripple that should avoid the rapid opening and closing owing to control valve 25 or 25 ' to cause.In Phase IV latter stage, it is the most key that valve head 58 drops on the valve seat gradually and accurately, because metal object will abut against each other.Thereby crucial is that exhaust valve 11 and piston 67 are little by little slack-off, thereby huge accelerating force is minimized, and avoid valve head to impinge upon on the valve seat.Exhaust valve 11 suitable opening curves can obtain in many ways according to the present invention.A kind of mode is the simple hydraulic actuator that is used for exhaust valve by using, for example the oil hydraulic cylinder (not shown) combines with the suitable control of proportional control valve, thereby so that the opening degree of the basically exclusiveness of proportional control valve guaranteed to be applied to suitable power on the exhaust valve and resistance is used for obtaining suitable opening curves by actuator.Another kind method is by using hydraulic actuator described herein and valve spring, and it has inherent characteristic, can obtain by the ON/OFF control valve so that be used for the suitable opening curves of exhaust valve.Actuator with inherent characteristic also can be combined with Proportional valve.

When exhaust valve will be opened and proportional control valve 25 when high-pressure liquid is fed to opening 70, and so that main pressurized chamber, middle pressurized chamber and the pressurization of auxiliary pressurized chamber.The high pressure hydraulic fluid of main pressurized chamber and auxiliary pressurized chamber so that piston be pressed downward.

Piston 67 (first piston part) is provided with piston cap 78 (the second piston portion).The top of piston 67 (near-end) slidably engages piston cap 78, thereby forms compensated chamber 79 between piston 67 and piston cap 78.According to preferred implementation, piston cap 78 is enclosed within on the top of piston 67.Yet piston cap 78 also can be arranged to be engaged in (not shown) in the top of piston 67.Spring 80 urges piston 67 and piston cap 78 makes it away from each other, thereby enlarges compensated chamber 79.The first flow path is arranged between compensated chamber 79 and the main pressure chamber 69.The first flow path comprises valve member 81, and valve member 81 is engaged in the receiving bore in the top of piston cap 78.Spring 80 upwards urges valve member 81 towards piston cap 78.According to another mode of execution (not shown), independent spring can be set be used for upwards urging piston cap 78 and valve member 81.This power that allows to be applied on arbitrary element can be regulated independently of one another.

Valve member 81 is provided with axial bore 82 and two radial holes 83 and 84, and these holes connect compensated chamber 79 and main pressure chamber 69, unless valve member 81 is located thereon the section position in receiving bore.At this upper position (Fig. 9 and 12), the wall of opening by receiving bore in hole 84 is stoped, thereby the first flow path is closed.The first flow path is used for allowing when piston 67 is located thereon the section position excessive hydraulic fluid 79 to overflow from the compensated chamber, and piston cap 78 is because the amount of hydraulic fluid in the compensated chamber 79 too much is set to the top than needed such more close main pressure chamber 69.In this case (Figure 10 and 11), valve member 81 be against the end surface of cylinder 66, and valve member 81 moves down with respect to piston cap 78, thereby open the first flow path, so that compensated chamber 79 can be emptying, until valve head 58 leans against on the valve seat.Thereby the first flow path is only just opened when piston element is positioned at little predetermined axial range at upper (closely) end place of cylinder 66.

The second flow path is between compensated chamber 79 and intermediate pressure chamber 71.According to preferred implementation, the second flow path is formed by the annulus 85 between piston 67 and the piston cap 78.Because annulus 85 is narrower, the second flow path has relatively high flow resistance.The second flow path allows compensated chamber 79 to be filled under the effect of spring 80.The suitable characteristics of the power by select being used for spring 80 and the resistance of flow path 85 obtains the suitable filling rule of compensated chamber.

Air refreshing tube 86 with high flow capacity restriction (flow restriction) is arranged on the top of cylinder 66, and the top of the main pressure chamber 69 that will be formed by dampening chamber 87 is connected to reflux line 43.

Piston cap 78 has the periphery of axial taper, and its diameter increases gradually towards piston head.Tapering part cooperates with inwardly outstanding annular flange flange 88, and annular flange flange 88 is led to the position of central hole at opening 70 and located above lucky and extend from central hole.Tapering part forms narrow annulus 89 with annular flange flange 88, and the size of annulus 89 changes along with the position of piston.Hydraulic fluid must pass this annulus 89 and be compressed, thereby flow to main pressure chamber 69 from middle pressure chamber 71.This is so that produce pressure drop between intermediate pressure chamber 71 and the main pressure chamber 69.This pressure drop raises during 89 size decreases in the annulus, and along with flow rate increases and increases gradually, thereby prevent that effectively piston 67 from arriving at a high speed.The size of tapering part so that annulus 89 towards the end of opening stroke and less.Towards the end of described stroke, thereby the speed of piston 67 is restricted effectively, even the supply pressure of hydraulic fluid is higher.Tapering part is shown in Fig. 9-11, and it has slightly bandy profile, but for example frustum of a cone, slightly aduncate profile, both combining form or the predetermined profile of any needs also are possible to other profile.This profile can pass through test method, computer emulation method or analytical method to be determined, described method representation should have much in each position and flow restriction of stroke, so that valve actuator has optimum dynamic property.Then, can correspondingly construct tapering part.

The downward power of actuator 19 and the power that makes progress of pneumatic spring 18 reach balance at the end to outer stroke, and namely piston 67 and exhaust valve 11 will self stop owing to them, shown in the Phase of Fig. 8.Neither need the supply of cutoff high HFO, also do not need stroke limiting stop to stop piston and exhaust valve.Because the supply of HFO does not need unexpected cut-out, thereby does not have the hydraulic shock ripple, otherwise, described hydraulic shock ripple will be oppressed whole hydraulic system.Do not have stroke limiting stop, thereby so that mechanical load and impact are lower.

Being fed to the pressure of HFO of hydraulic actuator 19 and the pressure that is fed to the air of pneumatic spring 18 is controlled as and guarantees that exhaust valve 11 arrives suitable open position.The size of actuator 19 and pneumatic spring 18 is arranged so that they are in the open position reverse power of balance easily.

During near the fully open position, the flow path between the tapering part of flange 88 and piston cap 78 narrows down at piston 67.Narrow slit has damping effect for the motion of piston 67, thereby piston stops at open position, and does not almost have or do not have at all to impact and vibration subsequently.

Piston 67 turns back to retracted position under the effect of pneumatic spring 18.Form with dampening chamber 87 is provided with the end of travel damping to hydraulic actuator 19 at the top of cylinder 66 (at near-end).The size at piston cap 78 tops forms with dampening chamber 87 and cooperates with micro-gap, and when the top of the second piston portion 78 is inserted in the dampening chamber, in return stroke, the micro-gap outflow dampening chamber 87 that is formed by annulus 90 by forcing hydraulic fluid to pass, thereby absorb most of kinetic energy of piston 67 and exhaust valve 11, and valve head 58 is located on the valve seat gently.

By changing the flow resistance that the flow path between opening 70 and the main pressure chamber 69 is regulated in the design of tapering part according to main pressure chamber 69 at the needed pressure in each position of piston 67.Thereby hydrovalve actuator 19 can cooperate well with the high-voltage power supply with change pressure.Relatively low supply pressure will cause lower valve acceleration.Therefore, electronic control unit 26 changes timing and the length of valve open continuously, changes with the pressure in the supply of compensation high pressure hydraulic fluid.When supply pressure is low, electronic control unit 26 will indicate proportional control valve 25 to open earlier and stay open longer a period of time, open long enough to guarantee exhaust valve, to discharge suitably the gas in the firing chamber, and when supply pressure was higher, vice versa.

Cylinder 66 comprises ventilation and recirculation conduit 86, and warm hydraulic fluid can pass actuator and circulate and turn back in the reflux line 43 thus.This is conducive to when motor does not move valve be remained on running temperature, and this can also remove air effectively.

The operation of hydrovalve

In the closed position of exhaust valve 11, piston cap 78 residing positions are: its top is positioned at dampening chamber 87 inboards and is positioned at the position range that valve member 81 allows.Figure 10 shows the highest possible position of piston cap 87, and wherein the first flow path is opened, and Figure 12 shows the minimum possible position of piston cap 78, and wherein valve member 81 is closed.In position range, between the wall of the top of piston cap 78 and dampening chamber 87, always there is a narrow annulus 90.

Exhaust valve 11 is opened by supplying high-pressure medium (HFO or fuel oil) from proportional control valve 25 (according to another mode of execution, for example the valve of other type of close/open valve 25 ' or servovalve can be used in the substitution ratio valve) to opening 70 (Figure 10).Thus, hydraulic medium flow through annulus 89 and annulus 90 and enter into main pressure chamber 69 and dampening chamber 87, and mineralization pressure and urge piston 67 downwards.The hydraulic fluid that flows out from opening 70 also flow into medial compartment 71, and enters into aux. pressure chamber 73 via axial passage 75.Thereby the pressure that acts on the enlarged diameter part 74 has increased the power that urges piston 67 downwards.

When on the piston 67 make a concerted effort to surpass the reaction force of pressure in pneumatic spring 18 and the firing chamber time, exhaust valve 11 begins to open.In the incipient stage of opening motion, pass annulus 90 and enter the restricted mobile low pressure that is formed in the dampening chamber 87 that produced in the dampening chamber 87, thereby the incipient stage of guaranteeing to open motion is level and smooth, does not have rapid acceleration and does not have the hydraulic shock ripple, referring to the Phase I of Fig. 8.

When exhaust valve 11 partially opens, the pressure in the firing chamber 15 and finish exhaust valve 11 and open needed power and obviously descend.In this stage, flowing of hydraulic fluid by being cut to aux. pressure chamber 73 by control flange 76, and simultaneously aux. pressure chamber 73 is connected to reflux line 43 via opening 77 and reduces to act on downward power on the piston 67, to allow to supply to aux. pressure chamber 73 in all the other stages of opening stroke from the hydraulic fluid of reflux line 43, allow the further expansion of aux. pressure chamber 73, thereby avoid in axial passage 75 and in aux. pressure chamber 73, air pocket occurring.

When the opening degree of exhaust valve 11 increased, the circulation area in slit 89 reduced.Thereby the pressure in main pressure chamber 69 and the aux. pressure chamber 79 reduces gradually.Pressure in the pneumatic spring 18 increases gradually simultaneously, thereby the velocity-stabilization ground of exhaust valve 11 reduces, until form good balance between the power that gentle moving medium applies by hydraulic pressure.Because relative hydrodynamic pressure little by little changes, exhaust valve 11 and piston are decelerated to fully smoothly and stop, and do not have any hydraulic shock ripple and Mechanical Contact, with reference to Fig. 8 Phase.The damping function of the circulation area that sharply reduces by slit 89 reduces near any oscillating movement of exhaust valve 11 fully open position.

During the opening stage of exhaust valve 11, valve member 81 is closed owing to the effect of spring 80 and against the downside of living piston cap 78.The amount that flows into the hydraulic fluid of compensated chamber 79 has guaranteed the predefine position of piston cap 78.Pressure difference between intermediate pressure chamber 71 and the main pressure chamber 69 and the power of spring 80 upwards urge piston cap 78, thereby a small amount of hydraulic fluid is inhaled between the compensated chamber 79 via the annulus 85 between piston cap and the piston.In the fully open position of exhaust valve 11, the pressure of main pressure chamber 69 and intermediate pressure chamber 71 equates, and only has spring 80 upwards to urge piston cap 78.Exhaust valve 11 open and fully during the opening stage, compensated chamber 79 refills so that piston cap 78 is upwards mobile lentamente with respect to piston 67.

Exhaust valve 11 cuts out again when coupling together in proportional control valve 25 change positions and with opening 70 and reflux line 43.The thrust of pneumatic spring 18 so that hydraulic fluid enter the reflux line 43 via annulus 89 from main pressure chamber 69.Little circulation area in the annulus 89 is guaranteed the soft start of return stroke, and during piston 67 moved upward, it had the stable speed that increases, and this speed is controlled by the stable increase of the circulation area of annulus 89, with reference to Fig. 8 Phase I.Because the pressure in the main pressure chamber 69 is higher than intermediate pressure chamber 71, incite somebody to action so that compensated chamber 79 dwindles a little via the discharge of annulus 85.Hydraulic fluid in the aux. pressure chamber 73 is emptying via opening 77, and when opening 77 is blocked by enlarged diameter part 74, emptying via axial passage 75, medial compartment 71, opening 70 and Returning pipe 43.

In the closing movement final stage, piston cap 78 is inserted in the dampening chamber 87, thereby formed annulus 90 has obviously reduced the available circulation area of hydraulic fluid in the dampening chamber.Hydraulic fluid in the dampening chamber 87 flows out dampening chamber via annulus 90, thereby it is used as braking force by the corresponding increase of pressure in the compensated chamber 79 at piston 67, thereby makes its deceleration, with reference to Fig. 8 Phase IV.In the compensated chamber 79 increase of pressure will so that some wherein fluid discharge via annulus 85.Thereby before exhaust valve 11 cut out, the speed that valve head 58 lands on valve seat went up by the circulation area of annulus 90 definite largely.Air refreshing tube 86 and annulus 85 more or less help fluid to flow out from dampening chamber 87.

If it is large that compensated chamber 79 has become during the opening stage of exhaust valve 11 fully, piston cap 78 will occupy to be inserted into it compares higher a little position in the dampening chamber 87.Thus, valve member 81 will be against the end (bottom of dampening chamber) of cylinder 66, and opens the first flow path, with emptying compensated chamber 79 (Figure 11), so that piston cap 78 can occupy correct position (Figure 10).

If shrink fully compensated chamber 79 during the return stroke of exhaust valve 11, piston cap 78 will occupy to be inserted into it compares lower a little position in the dampening chamber 87, and valve member 81 will be not against the end (Figure 12) of cylinder.Until next opening stage; spring 80 just can upwards urge piston cap 78; thereby compensated chamber 79 will admit the amount of hydraulic fluid that flows out via annulus 85, until valve member 81 is against the end (Figure 13) of cylinder 66, and guarantee that piston cap 78 occupies position roughly placed in the middle in its axial range.

Piston cap 78 moves under different temperatures so that hydraulic actuator 19 automatically compensates with the operation of compensated chamber's 79 combinations, finishing---and be the grinding of valve seat and the dimensional changes that foozle produces.Thereby valve head 58 will always softly and accurately land on valve seat.

According to an embodiment of the invention, hydraulic actuator 19 also can be embodied as does not have the compensated chamber as shown in Figure 7.It is not too important motor that this mode of execution can be used for the dimensional changes compensation, for example when as the general hydraulic fluid of hydraulic fluid when moving for 30-60 ℃.

Although for illustrative purposes detailed description the present invention, it will be appreciated that these details only are that those skilled in the art can make version in the situation that does not depart from scope of the present invention for the purpose of explaining.

Claims (5)

1. the method for temperature of fuel in the pressure piping (20) of a control crosshead type large two-stroke diesel engine (1), described pressure piping (20) is connected to hydrovalve actuator (19) with common fuel rail (40), and described method comprises the steps: during the running temperature of described fuel changes, control enters into the temperature of the fuel of described pressure piping (20), maintains under the predetermined threshold with the temperature gradient with described fuel.

2. the method for claim 1, wherein, the running temperature of described fuel from the fuel temperature of motor run duration during change the fuel temperature that is used for making during the engine stop described fuel circulation, the temperature gradient of described fuel remains between 0 ℃/minute to-2 ℃/minute.

3. the method for claim 1, wherein, the running temperature of described fuel from the fuel temperature that is used for making during the engine stop described fuel circulation during change the fuel temperature of motor run duration, the temperature gradient of described fuel remains between 0 ℃/minute to 2 ℃/minute.

4. method as claimed in claim 2, wherein, the fuel temperature of motor run duration is used for the fuel temperature of circulation between 45-60 ℃ during the engine stop between 90-150 ℃.

5. the method for claim 1, wherein described fuel temperature is controlled by the preheater (31) in the fluid circuit of the upstream that is arranged on high pressure fuel pump (33).

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